Portable heart monitor



FIG. 1 is a front elevational view of the design of a portable heart monitor;

FIG. 2 is a front side perspective view thereof;

FIG. 3 is a top elevational view thereof;

FIG. 4 is a right side elevational view thereof; and,

FIG. 5 is rear side perspective view thereof.

The broken lines in FIGS. 1-5 are included for the purpose of illustrating portions of the portable heart monitor that form no part of the claimed design. 

The ornamental design for a portable heart monitor, substantially as shown and described. 